Mix flour, butter, cinnamon, vanilla sugar, sugar, and salt together until sandy.
Add eggs and mix briefly. Form a flat ball and wrap in plastic wrap.
Let it chill for 1 hour in the refrigerator.
Peel all the apples and remove the core with an apple corer.
Cut in half and slice into thin slices, keeping them stuck together.
1 apple is cut into small cubes and the less pretty slices are also cut finely.
Combine them in a bowl, mix in sugar and cornstarch, and stir well together.
Roll out the dough evenly with some flour. It can also be done between 2 sheets of baking paper if you're not confident, that works too.
Line your pie pan with it. Press well into the sides, roll over your baking pan with the dough. This way you cut the dough to fit. With the rest of the dough, cut strips to decorate the sides; if it's too sticky or soft, put it back in the fridge to firm up.
Evenly distribute the finely chopped apple mixture over the bottom.
Take the apple slices, press them a bit apart, and lay them overlapping on top.
Brush some melted butter over the apples and decorate the sides with crisscross strips of dough.
Beat the yolk with some water and brush the edges of the dough with it.
Bake for 1 hour at 165-170°C until the apples are nicely colored.
Let the pie cool. By the way, it also goes well with a scoop of vanilla ice cream, haha.